Use of an Hydrometer

Radio Record, Volume II, Issue 53, 19 July 1929, Page 39

Use of an Hydrometer

[THs élettrolyte in accumulator cells consists of a mixtute of sulphuric acid and water.in certain proportions. When a battery is in use, the amount of electrolyte in the cells diminishes ; but: this ig merely because water -has evaporated, and not because any of the acid has been lost. Therefote, in order to make up for this evaporation, it-is only necessary to add pure distilled water. Never add acid':unléss you -have actually spilt ‘some, -'The distilled water’ can be pur‘chased from any garage or batterycharging station. Be sure that you get pure water, and nevér attempt to fill your battery cells with water obtained from the tap. : The water may be added to the battery with the aid of an ordinaty hydrméter, an instrument which may be

purchased from most radio shops. This instrument is made for the purpose of testing accumulators, to show how néarly they are fully charged. You ‘will find that the hydrometer usually consists of a syringe-like arrangement arranged with a float inside the tubular part. On squeezing the rubber bulb, placing the rubber tube in the hole provided in the top of a cell or a storage battery, and releasing the bulb, it will be found that a quantity of the electrolyte will be drawn up into the cylinder., The float will start to rise and, when it is completely off the bottom of the cylinder, it will be found. that one of the graduations on the scale of the float will be at: the top level of the liquid. This scale division denotes the condition of. the battery. By occasionally checking the condition of your battery with the hydrometer, going over every cell at eath test, you can determine exactly when it is nécessary to change it,